Atari 2600 Jr. - Bad TIA or RIOT?

[Sir Guntz]

I'll try to get some pictures or a video to better describe this.

 

Some time ago I bought an Atari 2600 Jr console (short rainbow version). It was sold as having graphical glitches with every game. I cleaned the cartridge slot very well. As of this time I've only tested the console with Armor Ambush.

 

In Armor Ambush, the game is visually sound, but on-screen action has problems. When moving either tank anywhere onscreen, they will flicker between the left and right halves of the playfield. Firing the cannon on either tank results in an instant hit no matter where the tanks are or where they're facing.

 

I think what's going on is there's problems with the playfield, players and missiles working properly in relation to the TV output. I don't think the CPU has anything to do with what's going on.

 

Can anyone wager a guess on which chip is failing here? I could also use a suggestion on where to buy replacement parts. I know arcadecomponents.com has 2600 Jr chips, but they might not ship to Canada.

[icemanxp300]

I would guess TIA over RIOT. I had a bad RIOT and screen was black. According to the info here the TIA controls the audio and video output.

 

http://blog.tynemouthsoftware.co.uk/2015/02/atari-2600-black-screen-repair.html

 

as far as where to buy, I made a wanted thread for a riot chip some time ago and was directed to jameco and the chips worked good maybe they have TIA chips as well?

 

http://atariage.com/forums/topic/254247-need-atari-2600-riot-chip/?hl=%2Briot&do=findComment&comment=3543864

 

The Jameco link is bad now for the RIOT chips but they may have something.

[Sir Guntz]

I tried the checkout at arcadecomponents.com and their postage to Canada is very reasonable $8.50 USD), so I went ahead and ordered a CO10444 TIA and since it was on sale, a CO10745 6507 CPU too.

[AtariLeaf]

Good to see replacements are available. Please keep us informed how the transplant goes once you get them and good luck